Electrical Engineering MCQs
Electrical Engineering MCQs are essential for aspirants preparing for engineering exams and job tests conducted by PPSC, FPSC, NTS, and other testing services. This section includes questions from power systems, basic electronics, circuit analysis, machines, measurements, and electromagnetism. Whether you're revising for an academic test or preparing for professional assessments, these multiple-choice questions are tailored to cover the entire Electrical Engineering syllabus. The content is designed to reflect current trends in competitive exams and industry requirements. Practicing these MCQs will help you strengthen your concepts, improve time management, and increase your chances of scoring high in electrical engineering exams in Pakistan.
Q: Power factor in purely inductive or capacitive circuit is
A) One
B) Unity
C) Negative
D) Zero
✅ Correct Answer: D
Explanation: Power factor is zero in such circuits as current and voltage are 90° out of phase
Q: The SI unit of magnetic flux density is
A) Weber
B) Henry
C) Farad
D) Tesla
✅ Correct Answer: D
Explanation: Tesla is the standard unit of magnetic flux density (B)
Q: A triac is used to
A) Rectify DC
B) Control AC power
C) Store data
D) Detect voltage
✅ Correct Answer: B
Explanation: Triacs control power flow in AC circuits, often used in dimmers and motor speed controls
Q: A diode allows current flow
A) Only under DC
B) In one direction
C) In both directions
D) Only under AC
✅ Correct Answer: B
Explanation: Diodes conduct current in one direction and block it in the reverse direction
Q: Transformer efficiency increases with
A) Higher temperature
B) Higher frequency
C) Smaller size
D) Lower losses
✅ Correct Answer: D
Explanation: Reducing core and copper losses improves transformer efficiency
Q: In a series RLC circuit, resonance occurs when
A) R = 0
B) XL = XC
C) R = XL
D) R = XC
✅ Correct Answer: B
Explanation: Resonance occurs when inductive and capacitive reactances are equal and cancel out
Q: The function of a Zener diode is to
A) Filter noise
B) Rectify current
C) Amplify signal
D) Regulate voltage
✅ Correct Answer: D
Explanation: Zener diodes are used in reverse bias for voltage regulation
Q: Superposition theorem applies to
A) Non-linear circuits
B) All circuits
C) Magnetic circuits
D) Linear circuits
✅ Correct Answer: D
Explanation: Superposition is valid only for linear networks with multiple sources
Q: Current through a capacitor
A) Lags voltage
B) Is always zero
C) Equals voltage
D) Leads voltage
✅ Correct Answer: D
Explanation: In capacitors, current leads voltage by 90°
Q: A synchronous motor runs at
A) Lower than synchronous speed
B) Variable speed
C) Zero speed
D) Constant speed
✅ Correct Answer: D
Explanation: Synchronous motors maintain a constant speed regardless of load